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Vertical welds with my mig ?

Hey all, another noob here.
I just purchased a M/M 252, i'm starting mig class at the local CC in early april. I was dying to get this thing fired up and run some beads.
A friend gave me a real cheap (free) welding table, it;s 30"x72" with a 3/8" top, it seems to be pretty straight/ flat but it's been sittins out in hes feild for a couple years.
It's proving to be quite the project, a kick in the but but pretty labor intense.
I'm adding quite a few add ons that i've seen on this forum, where i'm having issues is my vertical welds ?
do I need to drop my volts down a hair, I'm getting my droopie puddles and it seems to be burning through on a couple of spots, when it does this I make a wider pool and it seems to cool enough to fill it. Any advise ?
I'm welding 2'x2' 1/8 tube, my settings are 17.5 volts and 247 feed speed, 030 wire. My index on the machine says start at 18v/250 feed but 18 was definatly too hot.
Thanks and I do love this 252, it seems to be very adjustable.

I use that machine almost everyday at work, that or the 251. When I do vertical welds my machine is set at 18.6 volts and wfs at 165-170. I keep it at these setting for any vertical weld i place. You may want to try a trigger up weld. pull the trigger let the weld fill up, release trigger, watch the color of the metal, as soon as it starts to fade(through the dark lense assuming your not using a autoshade) move up right into the root where your last puddle ended and pull the trigger let the puddle fill again, then release trigger. Repeat until weld is finished. Does that make sense?

I use that machine almost everyday at work, that or the 251. When I do vertical welds my machine is set at 18.6 volts and wfs at 165-170. I keep it at these setting for any vertical weld i place. You may want to try a trigger up weld. pull the trigger let the weld fill up, release trigger, watch the color of the metal, as soon as it starts to fade(through the dark lense assuming your not using a autoshade) move up right into the root where your last puddle ended and pull the trigger let the puddle fill again, then release trigger. Repeat until weld is finished. Does that make sense?

Well i figured he is only modifying a welding table. No ones life should be on the line with this project if a weld fails. I was thinking about this all day at work too. I know that's not proper welding so I should not have told him that. I actually do this alot at work when working with the 1.5"X1.5"X1/6" square tube. I would never do that on something that could kill or injure someone if the weld was to fail. So none of the stuff i do at work like that is critical in that sense.
To be honest, i'm not sure why it's improper welding. I would love to know. Maybe I will never do it again if i understood.

What you get is a series of "cold starts" and a poor weld. I can't believe that that's acceptable in any production environment. Bad advice.

Straightshot,

You will normally run a little less v/a(ws) when welding vertical up than you would in the flat position.

I use a MM251 but your 252 should be similar. Try setting the Volts at 16.5-17.00 and your WS to 235-280. Use a small whip from side to side, only pausing briefly at the edges and not in the center of the joint. Come up slightly with each side to side whip. The weld bead should be continuous.

You may wish to download Miller's GMAW instruction manual on technique for welding vertical up. It's available under resources at the top of the page, or better yet, go ahead and order their "Student Pack". It will be the best $25 you spend in welding.

I'd recommend practice on some scrap stock before you go to the table itself.

I appreciate the info guys, I will check Millers site and check the student pack.
I did kick the volts down to 16.7 and inched the wfs up to 260, it worked quite a bit better.
I need to practice my steady hand, I been doing a C motion and I noticed I needed to speed across the gap and stall on the edges.
I've been watching this forum for months and can honestly say you guys are pretty cool..
I'll try and get some "before & after' pic's up, if I can figure out how to do it ?
Thanks again Jon

Vertical-Up

Originally Posted by Straightshot

I appreciate the info guys, I will check Millers site and check the student pack.
I did kick the volts down to 16.7 and inched the wfs up to 260, it worked quite a bit better.
I need to practice my steady hand, I been doing a C motion and I noticed I needed to speed across the gap and stall on the edges.
I've been watching this forum for months and can honestly say you guys are pretty cool..
I'll try and get some "before & after' pic's up, if I can figure out how to do it ?
Thanks again Jon

Jon, Hi;
Sounds like your getting the idea of welding Vertical-up !
Yes pause on the sides , But Do not Jump across, Weld Across to the
Sides!! You Will get It !

When welding vertical up, check the door chart for the next size down material. That will generally get you real close.

Too many variables for me to send you the exact numbers I would use on my machine in my shop. They include the input power to the machine, length of gun lead, wire manufacturer, etc, etc. That's why I normally will give a range and let you tweak from there.

Glad it's working out for you. The MM252 is a great mig welder. Are you using the M25 gun or have you gone to the Bernard Q-300's. If you're using the M25 you can still convert your gun to use the Bernard Centerfire tips. They are great. Much more durable tip than the standard ones.

I have the same "new" 252 and I had the same problem initially and I found that it did run a little hotter then the "door chart" when running uphill with .030 wire. I foud that I couldn't run straight up very well using the same technique I used to use years ago with a transformer power supply/wire feed.
I found it worked great with a rapid weave as described (very important to hold a short arc and stickout.

(Sundowner), I have ordered the Bernard Centerfire frontend components for the M-25. I don't know what the difference is but I found I had much better control of the heat with this machine using .035 wire in all positions (so far) Mind you I only have limited time on the new machine and I am Loving it more and more!

Straightshot, you are going to love this machine (with the lightweight tube) you may be more comfortable running those welds downhill, you can accomplish it straight down the root with a short arc and slight cant up staying just on the leading edge of the puddle!

Thanks Guys

Sundown, Norm, Tim, Jeep. Thank you ,
I do love this machine !
I will try the next step down method and hopefully adjust up from there.
I'm getting better on the vertical, but definatly need more practice.
My table is almost complete , just adding on some features seen on this forum.
I have to build a chopsaw stand next.
Sundown,Tim, any idea what it cost to convert to the Bernard ends ?
I did have my first lesson on melting the wire to the tip, twice! about an hour of weld time apart.
The first time it happened I scratched my head for a few min. on why my wire stopped feeding, hit the Miller Manual and figured it out real quick.
Thank you all again.. Jon